The invention relates to a method of processing identification signals in a data signal (teletext signal) which is cyclically repeated within a television signal and can be displayed in the form of single still television pictures.
The data signal, referred to as teletext signal, which is cyclically repeated within a television signal and is transmitted in the so-called data lines of the television signal constitutes a system of teletext pages comprising all kinds of information. Some of the teletext pages which are preview pages or so-called index pages at least substantially indicate their contents and provide information about other teletext pages with, for example detailed messages and other particularities. The index pages are used for guidance of the user who can select the indicated page numbers by means of keys on the display device or a handheld unit and display them on a display device. In the case of a larger data content leading to a larger division of the data on different teletext pages a plurality of index pages often has to be selected via the keys on the handheld unit until the actually selected information is displayed on the display device. Entering numbers for this so-called paging in the teletext pages, particularly in the case of considerably dissected information, requires a great deal of concentration on the part of the user, because each entry error leads to the wrong teletext page and usually causes a return to the index pages, thus necessitating a new selection procedure.